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排序方式: 共有984条查询结果,搜索用时 15 毫秒
41.
Are there two biological parts in the second stage of labor? 总被引:1,自引:0,他引:1
F Piquard A Schaefer R Hsiung P Dellenbach P Haberey 《Acta obstetricia et gynecologica Scandinavica》1989,68(8):713-718
In 228 patients, fetal blood pH, pCO2 and lactic acid were measured in two distinguishable parts of the second stage of labor. The 'first' part begins at full cervical dilatation and ends when the mother starts her first voluntary bearing down efforts. In our study, the fetal acid-base status did not change in this part, regardless of a late developing hypoxia. In contrast, higher levels of lactic acid and pCO2 and lower pH values were observed in the 'final' part of the second stage, indicating increasing acidosis. In this 'final' part, the fetuses with clinical signs of distress, as defined by an ominous Apgar score at birth, showed quicker and larger acid-base shifts than did the normal fetuses. Thus the two parts of the second stage of labor actually differ in their potential to stimulate fetal acidosis. Since such fetal acidosis may develop especially during the 'final' part of labor, we have concluded that special particular attention should be devoted to this part. 相似文献
42.
Hsiung SH 《Dermatology online journal》2003,9(4):39
Granuloma faciale is characterized by indurated, red-brown papules and plaques that usually occur on the face. We present a 52-year-old man with typical clinical and histologic features of this condition. A review of treatment options is presented. 相似文献
43.
Yih‐Ju Yang Tzu‐Hsien Liag Song‐Hsiung Lin Hsin‐Cheng Chen Shih‐Chan Lai 《Clinical & experimental optometry》2006,89(1):40-44
A 62‐year‐old woman presented with unilateral eye swelling and itching. Subsequent examination showed the cause was an infestation of the parasitic worm Thelazia callipaeda. The vector leading to human infection is the fly. The possible mechanisms of infection for this patient are discussed. Although this is a known form of ocular infection, especially in Asia, this is one of few reported cases in Taiwan. 相似文献
44.
A DNA endonuclease, isolated from the nuclei of normal human and xeroderma
pigmentosum complementation group A (XPA) cells, which recognizes
predominately pyrimidine dimers, was examined for the mechanism by which it
locates sites of damage on UVC-irradiated DNA. In reaction mixtures with
low ionic strengths (i.e. lacking KCl), the normal and XPA endonuclease
locate sites of UV damage on both naked and reconstituted nucleosomal DNA
by different mechanisms. On both of these substrates, the normal
endonuclease acts by a processive mechanism, meaning that it binds
non-specifically to DNA and scans the DNA for sites of damage, whereas the
XPA endonuclease acts by a distributive one, meaning that it randomly
locates sites of damage on DNA. However, while both the normal and XPA
endonucleases can incise UVC irradiated naked DNA, they differ in ability
to incise damaged nucleosomal DNA. The normal endonuclease showed increased
activity on UVC treated nucleosomal DNA compared with naked DNA, whereas
the XPA endonuclease showed decreased activity on the damaged nucleosomal
substrate. Since a processive mechanism of action is sensitive to the ionic
strength of the micro-environment, the KCl concentration of the reaction
was increased. At 70 mM KCI, the normal endonuclease switched to a
distributive mechanism of action and its ability to incise damaged
nucleosomal DNA also decreased. These studies show that there is a
correlation between the ability of these endonucleases to act by a
processive mechanism and their ability to incise damaged nucleosomal DNA;
the normal endonuclease, which acts processively, can incise damaged
nucleosomal DNA, whereas the XPA endonuclease, which acts distributively,
is defective in ability to incise this substrate.
相似文献
45.
Epidemiological evidence indicates that aflatoxin B1 (AFB1) intake is
associated with an increased risk of hepatocellular carcinoma (HCC). The
hepatocarcinogenesis is initiated by covalent binding of AFB1 to cellular
DNA. To determine whether nutritional factors and hormonal status may
influence the binding of AFB1 to hepatic DNA, a cross- sectional study was
performed on a total of 42 male asymptomatic hepatitis B surface antigen
(HBsAg) carriers and 43 male non-carriers in a cohort study on the
multistage development of HCC in Taiwan. The major AFB1-DNA adduct in vivo,
AFB1-N7-guanine, was measured by high- performance liquid chromatography in
urine. Urinary AFB1-N7-guanine was detectable in 40% of the subjects. HBsAg
carriers had a higher detection rate of urinary AFB1-DNA adducts than
non-carriers and the difference was statistically significant after
multivariate adjustment. After taking into account the total AFB1 urinary
metabolite level, chronic HBsAg carrier status, and other potential
confounders, plasma levels of cholesterol, alpha-tocopherol, and alpha- and
beta-carotene were positively associated with the detection rate of the
AFB1-DNA adducts in a dose-dependent manner, whereas plasma lycopene level
was inversely related to the presence of the adducts in urine. The
association of urinary AFB1-DNA adducts with the plasma levels of
cholesterol, alpha-tocopherol, lycopene, and alpha- and beta-carotene was
observed at both low and high exposure levels of AFB1. There was a
synergistic interaction of plasma alpha-tocopherol with alpha- and beta-
carotene on the adduct levels. No association with the adducts was found
for plasma levels of retinol and testosterone. This study demonstrated
different associations of antioxidant vitamins with AFB1- DNA adduct
formation. The data consistent with our previous finding in cultured
woodchuck hepatocytes that alpha-tocopherol and beta-carotene enhanced
AFB1-DNA adduct formation suggest that prospective investigation of the
relationship between plasma micronutrients and risk of AFB1-related HCC is
warranted.
相似文献
46.
LO Larsson MW Bentzon K Berg Kelly L Mellander B-E Skoogh I-L Strannegård A Lind 《Acta paediatrica (Oslo, Norway : 1992)》1994,83(10):1091-1094
We studied 3592 Swedish schoolchildren, 8 or 9 years old, examined for palpable submandibular, cervical and supraclavicular lymph nodes. All children were skin tested with 2 TU PPD RT23 and with 0.1 μ g of Mycobacterium avium sensitin or 0.1 μ g of M. scrofulaceum sensitin. A total of 991 children had palpable lymph nodes in any of the three locations. Among them, 811 had lymph nodes in one location, 162 in two locations and 18 in three. In 312 children, the lymph nodes were ± 5 mm in size in any location. The most common location was submandibular. Boys had a significantly higher prevalence of palpable lymph nodes than girls. There was also seasonal variation. Children infected by atypical mycobacteria (sensitin reaction ±6 mm) did not have a higher prevalence of palpable lymph nodes than those not infected. 相似文献
47.
48.
Actinic keratoses (AKs) represent the second most common reason to visit a dermatologist in the United States and their therapy has become a major portion of most dermatologists' practice. An ever-increasing array of therapeutic options exist for the therapy of actinic keratoses, offering physicians and patients a greater number of choices than ever before. Patient expectations and needs seem to be changing at the same time, thus effecting therapeutic decision-making. While destructive therapies with resultant wounds, time for wound healing, and possible hypopigmentation or scarring were acceptable in the past, many patients from the baby-boom generation are now developing AKs and have little tolerance for any time for wound healing or any cosmetic changes. This paper will raise some fundamental questions regarding AKs and their management. 相似文献
49.
Hsiung HM Hertel J Zhang XY Smith DP Smiley DL Heiman ML Yang DD Husain S Mayer JP Zhang L Mo H Yan LZ 《Endocrinology》2005,146(12):5257-5266
alphaMSH has generally been accepted as the endogenous ligand for melanocortin 4 receptor (MC4R), which plays a major role in energy homeostasis. Targeting MC4R to develop antiobesity agents, many investigators have performed a structure-activity relationship (SAR) studies based on alphaMSH structure. In this report, we performed a SAR study using human betaMSH (5 - 22) (DEGPYRMEHFRWGSPPKD, peptide 1) as a lead sequence to develop potent and selective agonists for MC4R and MC3R. The SAR study was begun with a truncation of N terminus of betaMSH (5 - 22) together with acetylation of the N terminus and amidation of the C terminus of the peptide. Introduction of a cyclic disulfide constrain and replacement of L-Phe with D-Phe afforded a super potent agonist (peptide 5). Furthermore truncation at the C terminus generated a small and potent MC4R and MC3R agonist (Ac-YRcyclo[CEHdFRWC]amide, peptide 6), which exhibited no MC5R and greatly reduced MC1R activity. Molecular modeling of Ac-YRcyclo[CEHdFRWC]amide (peptide 6) revealed that Arg2 in the peptide formed a salt bridge with Glu4. Subcutaneous or intracerebroventricular administration of peptide 6 in rats showed potent in vivo efficacy as evidenced by its effects in reducing energy balance, increasing fat use, and decreasing weight gain in both acute and chronic rat metabolic studies. Furthermore, the antiobesity effect by peptide 6 was manifested only in wild-type but not MC4R-deficient mice, indicating that antiobesity effects of the peptide were attributed largely through MC4R but not MC3R agonist activity of the peptide. 相似文献
50.
Issam E. Cheikh Bruce P.M. Hamilton Tah Hsiung Hsu John G. Wiswell 《Psychoneuroendocrinology》1981,6(1):37-44
(1) During an investigation of their pituitary function, the TSH prolactin (PRL) and gonadotropin, (LH, FSH) response to TRH was measured in four patients with documented euthyroid Klinefelter's syndrome. (2) In all four patients, the serum testosterone was low, the gonadotropins were elevated and thyroid antibodies undetectable. (3) The identical study was repeated after each patient had received intramuscular testosterone cypionate 200 mg bi-weekly for three doses. This raised the serum testosterone at least four-fold. (4) Basal TSH was normal in all four patients but its response to TRH was blunted (mean peak TSH 9.6 μU/ml), compared with normal controls (mean peak TSH 18 μU/ml). Following testosterone this response to TRH was further suppressed to a mean peak of 3.4 μU/ml TSH. (5) Basal PRL levels were also normal and the mean peak response to TRH, 28 ng/ml. When repeated after testosterone, TRH produced a mean peak PRL of 58 ng/ml. (6) LH and FSH, both elevated basally, did not change with TRH administration, but both were stimulated by LHRH 100 μg i.v., LH briskly, FSH more variably. (7) FSH was suppressed sharply but LH only partially with testosterone therapy. (8) Our studies indicate that the TSH response to TRH in Klinefelter's syndrome is blunted and further suppressed with short term testosterone replacement. The PRL response to TRH under these same circumstances, however, is enhanced. Previous reports of abnormal LH feedback control are confirmed. (9) Klinefelter's syndrome is associated with subtle abnormalities in hypothalamic pituitary regulation not expected in typical primary hypogonadism. 相似文献